JP2000005069A - Pot - Google Patents

Abstract

PROBLEM TO BE SOLVED: To permit the driving noise of a motor-driven pump in a refluxing operation to be smaller than that of the motor-driven pump in a hot water supplying operation. SOLUTION: In a pot 1 provided with the motor-driven pump 6 having a water pouring function pouring hot water 10 inside a liquid container 3 from a pouring port 8 and a refluxing function refluxing water in a pouring tube 5 to the liquid container 3, the rotational speed of the motor-driven pump 6 at the time of the refluxing operation is made lower than that of the motor- driven pump 6 at the time of pouring water.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a pot provided with an electric pump.

[0002]

2. Description of the Related Art Conventionally, there is a pot for supplying hot water by heating water in a liquid container provided inside a main body to a predetermined temperature. In addition, when the water in the liquid container is heated, the water is passed through a water purifier to purify the water (water purification operation), and at the time of hot water supply, the lukewarm water remaining in the water supply pipe between the liquid container and the water inlet is provided. Is provided with a "hot function" in which the water is heated after being refluxed into a liquid container (reflux operation) and only hot water heated to a predetermined temperature is supplied. In the pot having the above-mentioned water purification function and hot function, the electric pump used for hot water supply is also used for the water purification operation and the reflux operation in order to reduce the weight and the production cost.

[0003] As described above, the rotation speed of the electric pump used for hot water supply, water purification, and reflux is almost the same during operation of hot water supply, water purification, and reflux. Along with this, at the time of hot water supply, at the time of water purification, and at the time of reflux, drive noises of substantially the same magnitude are generated.
In the hot water supply operation, the user recognizes that driving noise is generated when the electric pump is operated, so the driver does not care much about the driving noise, but water purification and reflux are determined by the pot control device. Therefore, the driving noise of the electric pump generated in such a case is very annoying.

In particular, when the timer of the pot is set so that the water is boiled early in the morning, the pot performs the water purification operation while the user is sleeping, so that the sleep of the user may be hindered by the driving sound of the electric pump. .

An object of the present invention is to reduce the driving noise of the electric pump at the time of reflux and water purification which is unpleasant for the user.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and a pot according to the present invention is a pot provided with an electric pump. The rotation speed of the electric pump in operations other than the above-described water injection operation is lower than the rotation speed of the electric pump in the water injection operation of injecting hot water from the water inlet.

A pot according to a second aspect is characterized in that the operation other than the water injection operation is an operation of returning the water in the water injection pipe between the liquid container and the water inlet to the liquid container.

The pot according to the third aspect is characterized in that the operation other than the water injection operation is an operation of purifying hot water in the liquid container through a water purification filter.

[0009] The pot according to claim 4 is characterized in that the rotation speed of the electric pump is reduced by lowering the voltage applied to the electric pump.

In the pot according to the fifth aspect, the rotation direction of the electric pump in the operation other than the water injection operation is opposite to the rotation direction of the electric pump in the water injection operation.

[0011]

According to the pot of the first aspect,
Since the rotation speed of the electric pump in the operation other than the water injection operation is lower than the rotation speed of the electric pump in the water injection operation, the driving sound of the electric pump in the operation other than the water injection operation is It is smaller than the driving sound. For this reason, the user does not experience discomfort due to the driving sound of the electric pump in operations other than the water injection operation.

[0012] In the pot according to the second aspect, the rotation speed of the electric pump during the recirculation operation is lower than the rotation speed of the electric pump during the water injection operation. Is smaller than the driving sound of the electric pump during the water injection operation. Therefore, even when the recirculation operation is performed in a situation not intended by the user, the driving sound of the electric pump does not cause discomfort to the user.

In the pot according to the third aspect, the rotation speed of the electric pump during the water purification operation is lower than the rotation speed of the electric pump during the water injection operation. Is smaller than the driving sound of the electric pump during the water injection operation. Therefore, even when the water purification operation is performed in a situation not intended by the user, the driving sound of the electric pump does not cause discomfort to the user.

In the pot according to the fourth aspect, the rotation speed of the electric pump is reduced by lowering the voltage applied to the electric pump. Thus, the driving sound of the electric pump can be easily reduced by reducing the applied voltage.

In the pot according to the fifth aspect, since the rotation direction of the electric pump in the operation other than the water injection operation is opposite to the rotation direction of the electric pump in the water injection operation, the operation other than the water injection operation and the water injection operation are performed. If the directions of hot water flow are different, the operations can be performed by the same electric pump, so that the cost can be reduced.

[0016]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 shows a pot 1 according to the present invention. The pot 1 includes a main body 2 substantially formed of a substantially cylindrical body with a bottom, a liquid container 3 housed inside the main body 2, and a lid 4 for closing an upper opening of the liquid container 3. I have. The side wall of the liquid container 3 is constituted by a double wall composed of an inner wall and an outer wall, and the vacuum layer 3a between the inner wall and the outer wall makes the liquid container 3 excellent in heat insulation. A water injection pipe 5 is provided between the main body 2 and the liquid container 3 along the vertical direction of the liquid container 3. The lower end of the water injection pipe 5 is connected to an electric pump 6 provided below the liquid container 3, and the upper end of the water injection pipe 5 is connected to a projecting part 7 that projects to the side of the upper part of the main body 2. It is guided and constitutes the water inlet 8. The bottom surface of the liquid container 3 and the electric pump 6 are connected by a discharge pipe 9.

The liquid container 3 is provided inside the liquid container 3.
Is provided with a heater (not shown) for heating the water (hot water) 10 stored in the heater. A temperature sensor 11 is provided in a concave portion formed on the bottom surface of the liquid container 3, and the temperature of the hot water 10 is detected by the temperature sensor 11. A control device 12 is provided below the liquid container 3, and the electric pump 6, the heater, and the temperature sensor 11 are connected to the control device 12. The pot 1 includes a transformer inside the main body 2 (not shown), and the transformer converts 100 V AC for home use into DC.
The voltage is converted to 12 V, and this is used as a drive power source for the electric pump 6.

An operation panel 15 is provided on the upper surface of the lid 4 as shown in FIG. The operation panel 15 is provided with a heat retention setting switch 16, a hot water supply switch 17, a lock release switch 18, a reboil switch 19, a liquid crystal display unit 20, and LEDs 21, 22, and 23.

The heat insulation setting switch 16 is a switch for setting the heat insulation temperature of the hot water in the liquid container 3.
Hot water 10 in the heater at 98 ° C, 95 ° C, 90
It is used to maintain the temperature of ° C or 80 ° C and to cut off the power supply to the heater. Further, when the heat retaining switch 16 is operated, the characters "high temperature", "standard", "saving", and "sencha" are displayed on the liquid crystal display unit 20 in accordance with each set thermal insulating temperature. In the pot 1, as described above, the liquid container 3 has excellent heat insulating properties, so that the hot water 10 is kept warm even when the power supply to the heater is cut off. The heat retention state is displayed on the liquid crystal display unit 20 with the letters “vacuum heat retention”.

The hot water supply switch 17 is a switch for performing a hot water supply operation, and the lock release switch 18 is a switch for releasing the lock of the hot water supply switch 17. The reboiler switch 19 is a switch used when boiling the hot water in the liquid container 3 again.

The liquid crystal display section 20 displays the characters "temperature" and "water supply" in addition to the above-mentioned characters corresponding to each set temperature. “Temperature” is displayed when indicating the temperature of hot water 10 in liquid container 3. The specific temperature of hot water 10 is represented by digital numbers. "Water supply" is displayed to prompt the user to supply water when the remaining amount of the hot water 10 in the liquid container 3 becomes equal to or less than a predetermined amount.

The LED 21 indicates that the pot 1 is in a squeezing / boiling operation.
Indicates that the pot 1 is set in the warm state LE
D. The LED 23 is an LED indicating that the hot water supply switch 17 is unlocked.

FIG. 3 shows a drive circuit 30 for the electric pump 6 of the pot 1. The drive circuit 30 includes three power supply lines 31, 32, and 33 of DC12V. Power line 3
1, a hot water supply switch 17 and two transistors 35 and 36 connected in series are provided. The power supply line 32 is provided with two transistors 37 and 38 connected in series similarly to the power supply line 31.
A transistor 39 and a Zener diode 34 are connected to the power supply line 33 in series.

The electric pump 6 is connected between the collector of the transistor 35 on the power supply line 31 and the emitter of the transistor 37 on the power supply line 32. Power line 3
The base of one transistor 36 is connected to the collector of transistor 38 on power supply line 32, and similarly, the base of transistor 38 on power supply line 32 is connected to the collector of transistor 36 on power supply line 31.

A control signal is inputted from the control device 12 to the base of the transistor 35 of the power supply line 31. The base of the transistor 37 of the power supply line 32 is connected between the collector of the transistor 39 of the power supply line 33 and the Zener diode 34. Further, a control signal is input from the control device 12 to the base of the transistor 39 of the power supply line 33.

Next, the hot water supply operation and the reflux operation will be described with reference to FIG.
The operation will be described in detail with reference to the operation explanatory diagram shown in FIG.

As shown in FIG. 4, when the water heater is started and the temperature sensor 11 detects that the water in the liquid container 3 has been heated to 90 ° C. (step S shown in FIG. 5).
1), the control device 12 turns on the transistor 39. When the transistor 39 is turned on, the transistor 37
The voltage applied to the base is reduced to 10 V by the Zener diode 34. As a result, the transistor 37 is turned on, and the DC motor of the electric pump 6
A voltage of 10 V is applied in the direction of arrow a so that the C motor rotates in the reverse direction. In this way, the DC motor rotates reversely twice at a voltage of 10 V (step S2), whereby the water supply pipe 5 is rotated.
The water inside is returned to the liquid container 3 and heated. At this time, the electric pump 6 reversely rotates for 5 seconds and then reversely rotates again for 5 seconds after a stop time of 10 seconds. When the electric pump 6 stops, the hot water 1 in the liquid container 3 is added to the water supply pipe 5.
0 flows backward.

The control device 12 calculates the temperature rise rate of the hot water 10 in the liquid container 3 to predict the boiling time of the hot water 10, and performs the second reflux operation three times 50 seconds before the boiling. Perform (Steps S3 and S4). At this time, a cycle in which the DC motor of the electric pump 6 reversely rotates at a voltage of 10 V for 5 seconds and then stops for 7 seconds is repeated three times. Thereby, the hot water 10 in the water supply pipe 5 is also heated to the same temperature as the hot water 10 in the liquid container 3. When the electric pump 6 stops, the hot water 10 in the liquid container 3 flows back into the water injection pipe 5.
In this way, the pot 1 can also heat the water in the water injection pipe 5 to the same temperature as the hot water 10 in the liquid container 3, so that only hot water can be supplied at the time of hot water supply.

The hot water supply operation in the pot 1 will be described in detail. When performing the hot water supply operation, the user turns on the lock release switch 18 (step S10 in the flowchart shown in FIG. 6). When the control device 12 confirms that the lock release switch 18 is turned on, the control device 12
Determines whether five minutes have elapsed since the start of heat retention (step S11), and whether five minutes have elapsed since the end of the previous hot water supply involving the reflux operation (step S12). If these conditions are not met, the hot water in the water injection pipe 5 is not cooled, and there is no need to perform the recirculation operation.

If it is determined in step S11 that five minutes have elapsed since the start of heat retention, and if it is determined in step S12 that five minutes have elapsed since the last hot water supply with the recirculation operation, control is performed. The device 12 reversely rotates the DC motor of the electric pump 6 at a voltage of 10 V for 5 seconds to return the hot water in the water injection pipe 5 to the liquid container 3, heats the hot water in the water injection pipe 5 to a heat retaining temperature, and keeps the hot water during hot water supply. Only hot water heated to a temperature is supplied (reflux operation / steps S13 and S15).

If the user turns on the hot water supply switch 17 (step S14) even when the reflux operation is being performed, the control device 12 stops the reflux operation and determines in step S16. Do. In this step S16, it is determined whether or not it is within 10 seconds after the lock release switch is turned on. If it is longer than 10 seconds, the control device 12 locks the hot water supply switch 17 (step S17) and returns. I do.

When it is determined that the time is within 10 seconds after the lock release switch is turned on (step S16), it is determined that the hot water supply switch 17 is turned on (step S1).
8), the controller 12 rotates the electric pump 6 forward to perform the hot water supply operation (step S19). Specifically, when hot water supply switch 17 is turned on, control device 12 turns on transistor 35. As a result, the transistor 38 is turned on, and the DC motor of the
When the voltage of V is applied, the DC motor rotates forward and the hot water in the liquid container 3 is injected from the water inlet 8.

As is clear from the above description, the pot 1
Drives the DC motor of the electric pump 6 at a voltage of 10 V in the recirculation operation, and drives the DC motor of the electric pump 6 at a voltage of 12 V in the hot water supply operation. Therefore, the rotation speed of the DC motor of the electric pump 6 in the recirculation operation is lower than the rotation speed of the DC motor of the electric pump 6 in the hot water supply operation. Therefore, the electric pump 6 in the recirculation operation
The driving noise of the DC motor is smaller than the driving noise of the DC motor of the electric pump 6 in the hot water supply operation.
If the recirculation operation is performed in a situation not intended by the user,
The driving noise of the DC motor of the electric pump 6 does not become annoying to the user. In addition, D of the electric pump 6
Since the rotation speed of the DC motor can be reduced by changing the voltage applied to the C motor, the driving noise of the DC motor can be easily reduced.

Next, a second embodiment according to the present invention will be described with reference to a pot 40 shown in FIG. In addition,
In the pot 40, the same portions as those of the pot 1 are denoted by the same reference numerals, and the description of the configuration will be omitted. A water purifier 41 extending above the liquid container 3 is connected to an upper part of the water purifier 5 provided in the pot 40, and a water purifier 42 is attached to an end of the water purifier 41.
An electromagnetic valve 43 that is driven by a control signal from the control device 12 is provided at a connection portion with the control unit 12.

The water purifier 42 is provided with a water purifier filter therein so that impurities and odors of water flowing into the water purifier 42 from the water purifier 41 can be removed.

FIG. 8 shows a drive circuit 45 for the electric pump 6 of the pot 40. The drive circuit 45 has four power supply lines 46, 47, 48 and 49 of DC12V. The hot water supply switch 17 and the transistor 3
5 and the electric pump 6 are connected in series. A control signal is input from the control device 12 to the base of the transistor 35 of the power supply line 46. The power supply line 47 is constituted by a transistor 37, and the emitter of the transistor 37 is connected to the collector of the transistor 35 of the power supply circuit 46.

The power supply line 48 has a transistor 39 and a zener diode 34 connected in series, and the collector of the transistor 39 is connected to the base of the transistor 37 on the power supply line 47. Further, a control signal from the control device 12 is input to the base of the transistor 39 of the power supply line 48. Power line 49
Is configured by connecting a transistor 50 and an electromagnetic valve 43 in series.

When hot water is supplied using the pot 40, the lock release switch 18 is turned on and then the hot water supply switch 17 is turned on, as in the case of the pot 1. Specifically, when the control device 12 determines that the hot water supply switch 17 is turned on within 10 seconds after the lock release switch 18 is turned on, the control device 12 turns on the transistor 35 and applies a voltage of 12 V to the DC motor of the electric pump 6. Then, the DC motor is rotated forward, and hot water in the liquid container 3 is injected from the injection port 8. When it is determined that hot water supply switch 18 has been turned on 10 seconds after control device 12 has turned on lock release switch 18, control device 12 locks hot water supply switch 17.

Next, the water purification operation will be described in detail with reference to the flowchart shown in FIG. When the control device 12 detects that the water in the liquid container 3 has been heated to 90 ° C. by the signal from the temperature sensor 11, the control device 12 turns on the transistor 50 and turns on the transistor 50. The valve 43 is driven to connect the water injection pipe 5 and the water purification pipe 41 (steps S20, S21).

Subsequently, the control device 12 controls the transistor 39
Turn on. When the transistor 39 is turned on, the voltage applied to the base of the transistor 37 is reduced to 10 V by the Zener diode 34. As a result, the transistor 37 is turned on, and the DC
The motor rotates forward for 30 seconds when a voltage of 10 V is applied (steps S22 and S23). In this manner, the DC motor rotates forward at a voltage of 10 V for 30 seconds, so that the hot water in the liquid container 3 is pumped up by the water purifier 42 via the water purification pipe 41 and is purified by the water purifier 42. It is returned to the liquid container 3.

In the pot 40, the pot 1
Similarly, in the hot water supply operation, the DC motor of the electric pump 6 is driven by the voltage of 12 V, and in the water purification operation other than the hot water supply operation, the DC motor of the electric pump 6 is driven by the voltage of 10 V. The rotation speed of the DC motor 6 is slower than the rotation speed of the DC motor of the electric pump 6 in the hot water supply operation. Therefore, the driving sound of the DC motor of the electric pump 6 in the water purification operation is smaller than the driving sound of the DC motor of the electric pump 6 in the hot water supply operation.

Therefore, for example, when the pot 40 is connected to a power source via a timer and the timer is set so that hot water is boiled in the early morning, the pot 40 performs the water purification operation while the user is asleep, but the water purification operation is not performed. D of the electric pump 6 generated at the time
Since the driving sound of the C motor is quiet, it does not prevent the user from going to bed. In addition, since the rotation speed of the DC motor can be reduced by changing the voltage applied to the DC motor of the electric pump 6, the driving noise of the DC motor in the water purification operation can be easily reduced. .

In the pot 40, the hot water in the water injection pipe 5 is returned to the liquid container 3 by the water purification operation, so that the water purification operation is performed during the water heating and before the hot water supply operation as in the case of the pot 1. Since the hot water 10 in the injection pipe 5 is heated to the same temperature as the hot water 10 in the liquid container 3, only the hot water can be injected. Also, pot 4
Even in the case of 0, the electric pump 6 is rotated in the reverse direction as in the case of the pot 1, so that the circulation operation is performed during the water heating and before the hot water supply operation, and only the hot water is supplied at the time of the hot water supply operation. Good.

Next, a third embodiment according to the present invention will be described with reference to FIG. In the pot 60 shown in FIG. 10, the same portions as those in the pots 1 and 40 are denoted by the same reference numerals, and the description of the configuration will be omitted. The pot 60 is a dedicated electric pump 61 for performing a water purification operation.
Is provided below the liquid container 3. This electric pump 61
Is connected to a discharge pipe 62 connected to the bottom surface of the liquid container 3 and a water purification pipe 63 provided along the vertical direction of the liquid container 3 at a position opposite to the water injection pipe 5 with the liquid container 3 interposed therebetween. It is. The upper end of the water purification pipe 63 is located above the liquid container 3, and the water purifier 42 is attached to the upper end.

FIG. 11 shows a drive circuit 65 for the electric pump 6 of the pot 60. The drive circuit 65 has three power supply lines 66, 67, and 68 of DC12V. The hot water supply switch 17 and the transistor 3
5 and the electric pump 6 are connected in series. A control signal is input from the control device 12 to the base of the transistor 35 on the power supply line 66.

The power supply line 67 is configured by connecting the transistor 37 and the electric pump 61 in series. The power supply line 68 includes a transistor 39 and a Zener diode 34.
Are connected in series, and the collector of the transistor 39 is connected to the base of the transistor 37 on the power supply line 67. A control signal is input from the control device 12 to the base of the transistor 39.

Since the hot water supply operation in the pot 60 is performed by applying a voltage of 12 V to the DC motor of the electric pump 6 in the same manner as the hot water supply operation in the pot 40, detailed description will be omitted.

When the water purifying operation for purifying the hot water 10 in the liquid container 3 is performed, the control device 12
Turn on. When the transistor 39 is turned on, the voltage applied to the base of the transistor 37 is reduced to 10 V by the Zener diode 34. As a result, a voltage of 10 V is applied to the DC motor of the electric pump 61, the DC motor rotates forward, and the hot water 10 in the liquid container 3 is pumped. The pumped hot water 10 flows into the water purifier 42 via the water purifier 63 and is purified by the water purifier 42 before being returned to the liquid container 3. The water purification operation of the pot 60 is the same as the water purification operation of the pot 40.
This is performed for 30 seconds when the hot water 10 in the inside is heated to 90 ° C.

In the pot 60, similarly to the pot 1 and the pot 40, the DC motor of the electric pump 6 is driven at a voltage of 12 V in the hot water supply operation, and the electric pump 61 is driven at a voltage of 10 V in the water purification operation other than the hot water supply operation. Is driven, the rotation speed of the DC motor of the electric pump 61 in the water purification operation is lower than the rotation speed of the DC motor of the electric pump 6 in the hot water supply operation. For this reason,
The driving noise of the DC motor of the electric pump 61 in the pot 60 is low, and it is possible to prevent the user from feeling uncomfortable.

In the pot 60, as in the case of the pot 1, if the reflux operation is performed using the electric pump 6 during water heating and before the hot water supply operation, only the hot water 10 is supplied during the hot water supply operation. Can be.

Next, a fourth embodiment according to the present invention will be described with reference to FIG. Pot 7 shown in FIG.
Regarding 0, the same portions as those of the pots 1, 40, and 60 are denoted by the same reference numerals, and the description of the configuration is omitted.

The water supply pipe 5, the discharge pipe 9 and the water purification pipe 63 of the pot 70 are connected to each other via the electric pump 6. During the hot water supply operation, the DC motor of the electric pump 6 rotates forward at a voltage of 12 V, and the hot water 10 in the liquid container 3 passes from the discharge pipe 9 through the water supply pipe 5 and is supplied from the water supply port 8.
Further, at the time of the water purification operation, the DC motor of the electric pump 6 reversely rotates at a voltage of 10 V, and the hot water 10 in the liquid container 3 is returned from the discharge pipe 9 through the water purification pipe 63 to the water purifier 42.
The pot 70 includes the drive circuit 30 provided in the pot 1, and the water purification operation is performed for 30 seconds when the hot water 10 is heated to 90 ° C., similarly to the water purification operation of the pot 40. Also in this pot 70, the rotation speed of the electric pump 6 in the water purification operation is low, and the driving sound of the electric pump 6 is small, so that the driving sound of the electric pump 6 does not cause discomfort to the user.

The driving voltage of the DC motor of the electric pumps 6 and 61 in the water purifying operation and the recirculation operation other than the hot water supply operation in the pots 1, 40, 60 and 70 is 10
V, the driving noise of the DC motors of the electric pumps 6 and 61 in these operations is smaller than the driving noise of the DC motors of the electric pump 6 in the hot water supply operation, and is unpleasant for the user. It is sufficient if the drive voltage is such that it disappears.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of a pot according to the present invention.

FIG. 2 is a plan view of an operation panel.

FIG. 3 is a drive circuit diagram of the electric pump.

FIG. 4 is an explanatory view of the operation of the pot according to the present invention.

FIG. 5 is a flowchart showing a reflux operation.

FIG. 6 is a flowchart showing a hot water supply operation.

FIG. 7 is a schematic sectional view of a pot according to a second embodiment.

FIG. 8 is a drive circuit diagram of a pot electric pump according to a second embodiment.

FIG. 9 is a flowchart showing a water purification operation of a pot according to the second embodiment.

FIG. 10 is a schematic sectional view of a pot according to a third embodiment.

FIG. 11 is a drive circuit diagram of a pot electric pump according to a third embodiment.

FIG. 12 is a schematic sectional view of a pot according to a fourth embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... pot, 2 ... main body, 3 ... liquid container, 6 ... electric pump, 8 ... water inlet, 10 ... hot water.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Tanaka Politics 1-20-5 Tenma, Kita-ku, Osaka-shi, Osaka Elephant-in-Mahobin Co., Ltd. (72) Inventor Hiroshi Kumagai 1-20, Tenma, Kita-ku, Osaka, Osaka No. 5 Elephant Sealed Mahobin Co., Ltd. F term (reference) 4B055 AA34 BA63 CA02 CB04 CC66 CD61

Claims (5)

[Claims] In a pot provided with an electric pump, an operation other than the water injection operation is compared with a rotation speed of the electric pump in a water injection operation of injecting hot water in a liquid container from a water inlet using the electric pump. A pot characterized in that the rotation speed of the electric pump is low. 2. The pot according to claim 1, wherein the operation other than the water injection operation is an operation of returning water in a water injection pipe between the liquid container and the water inlet to the liquid container. 3. The pot according to claim 1, wherein the operation other than the water injection operation is an operation of purifying hot water in the liquid container by passing the same through a water purification filter. 4. The pot according to claim 1, wherein the rotation speed of the electric pump is reduced by lowering a voltage applied to the electric pump. 5. The rotation direction of the electric pump in an operation other than the water injection operation is opposite to the rotation direction of the electric pump in the water injection operation.
The pot according to 3 or 4.